This invention relates to carburetor and more particularly to apparatus for venting fuel vapors from a fuel bowl of a carburetor.
Carburetor assemblies typically include a fuel bowl which holds fuel, e.g. gasoline, that is supplied to the engine on which the carburetor is installed. When the engine is shut off after running for some time, a "hot soak" condition exists in which heat from the engine elevates the temperature in the fuel bowl causing the gasoline to give off vapors. As the engine gradually cools off, the fuel bowl temperature also decreases and increasingly smaller amounts of vapors are produced. If the fuel bowl is vented, the vapors produced boil out of the fuel bowl through the vent and may, for example, accumulate in the air space adjacent an air induction passage of the carburetor. Over time, the vapors saturate this air space and may gravitate into the intake manifold of the engine displacing the air in this region. Consequently, when the engine is next started, an overly rich air-fuel mixture is supplied to it making the engine difficult to start and increasing the amount of pollutants emitted from the engine during starting.